Yes.
In that case change your BIOS boot order to
0. CD/DVD ( you need to boot from the Ubuntu CD to install )
1. EMPTY HDD ( this should show up as /dev/sda under the ubuntu installer after you change the BIOS boot order, although your BIOS may vary )
2. VISTA HDD or NONE ( this should show up as /dev/sdb and should show your Vista partitions )
3. NONE
4. NONE
When you get to the Ubuntu partitioner make sure you do not make any changes to your vista drive.
Create the partitions on the empty drive and then install GRUB on that same drive and not the vista drive with the NTFS partition.
If you haven't got a backup of your vista system now may be a good time to do it before you do anything else.
Good luck